This invention concerns traction enhancing cleats for attachment to boots or shoes, particularly for flexible boots or shoes, functioning as a soft-boot crampon engaged under the ball of the foot but not the heel. In another aspect, the invention concerns such a terrain-engaging cleat which, when worn on a boot, can be secured to a snowshoe by stepping into the snowshoe, serving as a front cleat for the snowshoe.
Crampons, ice creepers and cleats for attachment to boots or shoes are very well known. For example, see U.S. Pat. Nos. 37,558, 754,577, 988,527, 1,045,565, 1,200,658, 1,230,118, 1,570,791, 1,728,783, 2,317,647, 2,358,066, 2,401,891, 2,579,143, 2,920,403, 4,005,533, 4,620,375, 4,745,692, 4,910,883, 5,787,612; French Patent No. 1,189,492 and German Patent No. DE 30 19 129 A1.
Conventional crampons essentially comprise rigid boot attachments which attach to the bottom of a boot sole by bales forming part of the crampons. These technical terrain-engaging devices require a substantially rigid boot, stiff like a downhill ski boot, because the crampon does not have any appreciable flexibility which could bend with the bending of a flexible boot. A crampon of this general type is shown in the above U.S. Pat. No. 4,910,883, and is also shown in the copending application Ser. No. 09/00948. The above U.S. Pat. No. 754,577 also shows an essentially rigid type of crampon device.
Various types of ice creepers or cleats have been proposed for use on flexible boots or shoes, as reflected in some of the patents listed above. U.S. Pat. Nos. 1,570,791, 1,728,783, 2,401,891, 2,579,143 and 4,005,533 all show such cleats or creepers which reside in the arch area of the shoe or boot, just ahead of the heel. The cleat devices of those patents are retained on the boots using straps. Some of these show angled teeth, including front teeth angled downwardly/forwardly and including teeth with faces obliquely angled so as to achieve some degree of lateral traction as well as fore/aft traction.
U.S. Pat. No. 988,527 shows a flexible shoe having a heel element and a separate toe element, both secured to the shoe and with a form of spikes, for use by carpenters, roofers, etc. to prevent the wearer from slipping.
U.S. Pat. No. 4,745,692 shows an anti-slip toe cleat device which has capability of pivoting or folding from one position to another. The hardware is permanently attached to the shoe, in the ball area.
U.S. Pat. No. 2,317,647 shows a strap-attachable ice creeper device which fits in the arch and ball area of the shoe or boot, with teeth positioned in the ball area of the foot. Some of the teeth are angled, and the cleat device apparently is useable on a flexible shoe or boot.
French Patent No. 1,189,492 discloses a simple form of ice creeper comprising a single strap that wraps around the toe area of the shoe or boot and which has, fitted onto the strap, two cleats side-by-side under the ball of the foot, each cleat having forward and rear racks of teeth.
U.S. Pat. No. 5,687,491, owned by the assignee of the present invention, describes a contoured footbed for the front portion of a boot, the footbed being on the top surface of a front claw or cleat of a snowshoe. That patent is incorporated herein by reference.
In climbing or steep terrain hiking in snowy and icy conditions, the climber often needs to switch from wearing snowshoes on the boots to crampons on the boots, and back to snowshoes as fields of deeper snow are again encountered. To change from ice crampons to snowshoes, the user normally has to release the crampon""s bales from front and back of the boot, remove the crampons and stow them in or on a pack, take out a pair of snowshoes from the pack, with their relatively heavy toe harness assemblies and cleats, and secure the snowshoes to the boots using several harness straps. In conditions where deep snow and ice are alternately encountered, the hiker or climber would be much better served if the crampon teeth could serve as the cleats for the snowshoes, and this is a primary object of the invention.
U.S. Pat. No. 4,620,375 disclosed a snowshoe wherein the user""s boot was secured to a binding on an ice crampon. The crampon had toe and heel cleats which passed down through openings in toe and heel areas of the snowshoe deck when the user""s boot was pivoted to the heel-down position, so that the crampon cleats served as cleats for the snowshoe. A horizontal pivot pin had to be assembled through the snowshoe frame and the crampon binding.
The copending application Ser. No. 09/00948 referenced above describes a snowshoe for receiving conventional crampons, the snowshoe having openings in its deck at front and rear. The snowshoe is adapted to receive a conventional crampon secured to a user""s boot in a step-in arrangement which was designed to afford fast and efficient securement of the boot and crampon to the snowshoe. The crampon""s teeth, both the front set and back set, then serve as snowshoe cleats. The snowshoe can quickly be removed from the boot and crampon when ice is encountered.
The described arrangement works well for those using rigid, full-boot crampons. However, there is also a need for a more versatile crampon or cleat, for use on a flexible boot which bends with walking of the user. In particular, there is a need for such a cleat which engages under only the ball area of the boot, using a harness which is conveniently secured to and removed from the boot. In addition, there is a need for such a soft-boot terrain-engaging cleat or crampon which has a further utility of engaging with a snowshoe having a dedicated receiving device in the front area of the snowshoe, to lock the cleat in position on the snowshoe firmly against rotation or looseness as in the system described above, and with the ability to conveniently engage the boot-attached cleat with the snowshoe and to easily remove it from the snowshoe.
In one aspect of the invention, a soft-boot cleat, serving as a toe-only crampon which engages under the ball of the foot, provides a relatively compact and lightweight terrain-engaging device which is easily attached to or removed from the boot or shoe. The terrain-engaging device or crampon has a platform including an upper surface with a footbed to receive the bottom of the front portion of a flexible boot or shoe, under the ball of the foot, such that the heel of the boot or shoe extends behind the platform. A plurality of teeth extend downwardly from edges of the platform, including left and right side teeth and at least two front teeth, the front teeth extending forward from the platform in an oblique manner such as in the front teeth of a conventional full-foot crampon. The device includes a harness assembly secured to the platform and extending laterally outwardly from forward and rear locations on the platform. This harness includes strap means for engaging over the top of a user""s boot including generally over the arch region of the boot, with buckling means for engaging the strap means firmly on the boot.
The terrain-engaging cleat device preferably further includes a heel strap connected to the harness assembly, for extending around the back of the user""s boot to connect to an opposite side of the harness, with a latch or buckle to secure the strap firmly around the boot.
In one preferred embodiment the platform and teeth comprise an integral stainless steel stamping, and this may include stiffener pleats in the bend areas where the platform extends down into the teeth, for added strength.
The harness assembly includes a web of flexible material secured to the platform, preferably to its bottom, and extending laterally outwardly and upwardly from the platform. Portions of the web at each side of the crampon extend from positions both forward of and behind the side teeth. The strap means are connected to the web.
In preferred embodiments the platform has a tail extension at its rear, defining a rear attachment point located approximately at the arch of the user""s shoe or boot. The web of the harness assembly, secured to the platform, has a rear portion secured to the rear attachment point on the tail extension. This provides a more secure binding to the boot, resisting rotation of the cleat relative to the boot.
An important aspect of the invention is a toe area terrain-engaging cleat or crampon in combination with a snowshoe which accepts the boot-worn cleat in a step-in arrangement, so that the user can quickly switch from simply using the terrain engaging cleat to wearing a snowshoe. This function and the structure which accomplishes the function are similar to the apparatus disclosed in the copending application Ser. No. 09/00948, incorporated herein by reference, and this is one form of the invention. However, the invention also encompasses another embodiment of a snowshoe/crampon combination using the soft-boot cleat or crampon described above. In this case the snowshoe does not have a deck opening in a rear area for rear crampon teeth, since the terrain-engaging cleat of the invention resides only in the toe area of the boot. The front portion of the snowshoe has a registry plate which is easily engaged by the cleat even while it is worn on the boot, without the registry apparatus being directly visible to the user. The front teeth of the terrain-engaging cleat are angled downwardly and forwardly, and these provide a tactile means for finding the associated apparatus on the snowshoe plate for correct registry. If the user fails to step into precisely the right position, this will be readily apparent because the cleat will not feel as if it is being lowered into the snowshoe for proper engagement.
In a preferred embodiment, the snowshoe has a pivoting front harness, which may be biased to the tail-down position of the snowshoe, the front harness including the rigid registry plate adapted to be received against the bottom of the cleat device and preferably a strap to extend over the top of the foot. The rigid plate has a specific shape designed to accommodate the pattern of teeth at the front end of the cleat device. The plate has a front portion which provides clearance at front and sides to receive teeth of the crampon down around the plate. The plate and the crampon structure are configured and sized in preferred embodiments such that the user must tip the toe of the boot and connected cleat device toe-down into the snowshoe to fit a front bar of the registry plate between teeth of the cleat; then, when the heel is rotated down, an angled tooth edge pivots under the front bar structure of the plate, the tooth structure becomes closely nested with the plate, and the front end of the cleat is thus locked in position against lifting from the plate. The configurations of the harness plate, and of the tooth structure, are such that the cleat device becomes oriented (with respect to rotation about a vertical axis) on the snowshoe as the teeth are inserted into the clearances and the heel is lowered.
Once the user has stepped the cleat and boot into the snowshoe as described, a single strap may be used to secure the boot down to the front harness assembly, preferably located approximately at the boot arch and extending over the top of the foot between the ankle and the ball of the foot. This strap preferably is mounted on the registry plate of the snowshoe harness.
It is thus among the objects of the invention to make more efficient the use of snowshoes and terrain-engaging cleats in traversing fields of ice and snow alternatively, by providing a snowshoe with a front harness plate configured to receive a terrain-engaging cleat or crampon in a step-in maneuver that enables very quick transition from ice trekking to snowshoeing. Another object is an efficiently used, lightweight terrain-engaging cleat for the ball area of the boot, with or without a snowshoe. These and other objects, advantages and features of the invention will be apparent from the following description of preferred embodiments, considered along with the accompanying drawings.